Add adding and detail

dealer/DataManager.cs

@@ -0,0 +1,47 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace dealer
+{
+    public class DataManager
+    {
+        private List<Vehicle> vehicles = new List<Vehicle>();
+
+        public void AddVehicle(Vehicle vehicle)
+        {
+            vehicles.Add(vehicle);
+        }
+
+        public IEnumerable<Vehicle> GetAllVehicles()
+        {
+            return vehicles;
+        }
+
+        public void RemoveVehicle(Vehicle vehicle)
+        {
+            vehicles.Remove(vehicle);
+        }
+
+        public void Save()
+        {
+            // Implementace ukládání dat do souboru - JSON
+            var json = System.Text.Json.JsonSerializer.Serialize(vehicles);
+            System.IO.File.WriteAllText("vehicles.json", json);
+        }
+
+        public void Load()
+        {
+            string path = "vehicles.json";
+
+            // Implementace načítání dat ze souboru - JSON
+            if (System.IO.File.Exists(path))
+            {
+                var json = System.IO.File.ReadAllText(path);
+                vehicles = System.Text.Json.JsonSerializer.Deserialize<List<Vehicle>>(json) ?? new List<Vehicle>();
+            }
+        }
+    }
+}